Global climate change concerns may necessitate capture of carbon oxide gases such as CO2, e.g., from flue gases and other process streams. One traditional approach involves absorption of CO2 with an amine solution, such as monoethanolamine (MEA), other ethanolamines, or certain amine mixtures, which solution is then thermally regenerated and recycled. This traditional approach is capital and energy intensive. There is considerable prior art in this area of conventional liquid sorption.
There is also some level of prior art regarding solid sorbents and rotary wheels. For example, there are the following scholarly articles: C. Y. Pan et al. Chemical Engineering Science. 22 (1967), 285: C. Y. Pan et al., Chemical Engineering Science, 25 (1970), 1653; Ralph T. Yang, Gas Separation and Adsorption Processes, Imperial College Press, 1997; Y. Matsukuma et al., “Study of CO2 recovery system from flue gas by honeycomb type adsorbent I.”, Kagaku Kogaku Ronbunshu, 32(2), 2006, 138-145; Y. Matsukuma et al., “Simulation of CO2 recovery system from flue gas by honeycomb type adsorbent: II. Optimization of CO2 recovery system and proposal for actual plant”, Kagaku Kogaku Ronbunshu, 32(2). 2006, 146; C. Shen et al. “Adsorption Equilibria and Kinetics of CO2 and N2 on activated Carbon Beads”. Chemical Engineering Science, 160 (2010), 398-407; Z. C. Liu et al., Carbon, 37 (4), 1999, 663-667; and G. Krishnan, “Development of Novel Carbon Sorbents for CO2 Capture”, presented at the 2010 NETL CO2 Capture Technology Meeting, 13-17 Sep. 2010, Pittsburgh, Pa. There are also the following patent-related publications: U.S. Patent Application Publication Nos. 2005/0215481, 2005/0217481, and 2009/0214902; U.S. Pat. Nos. 4,778,492, 6,500,236, 6,596,248, 6,521,026, 6,783,738, 7,022,168, and 7,166,149; European Patent Nos. EP 1138369 and EP 2258879; Japanese Patent Publication No. 2003181242; and Japanese Patent No. 4414110.
It would be highly desirable to employ a sorption method that is less capital and energy intensive than conventional liquid amine sorbents and that can provide an efficiency advantage.